1. Field of the Invention
The invention relates generally to the field of digital image processing and, more specifically, to a crosstalk filter in a digital image processing pipeline.
2. Description of the Related Art
Digital cameras typically include an image sensor with an integrated color filter array, such as a Bayer filter mosaic. The image sensors generate raw image sensor data where each pixel location in the raw image sensor data stores the intensity of light corresponding to a particular color channel. A well-known problem with such image sensors is that spectral, optical and electrical crosstalk between neighboring pixel locations causes poor color separation and a reduction of spatial resolution in the resulting digital image. These effects are caused by light hitting one pixel location that then generates an intensity value across multiple adjacent pixel locations.
To correct for the poor color separation arising from crosstalk, many digital image processing pipelines implement a color correction processing block. In such implementations, color correction processing is performed on pixel data in a digital image after the raw data captured by the image sensor has been interpolated through a process called demosaicing. With demosaicing, each pixel location in the digital image stores an intensity value for each of three distinct color channels (red, green, and blue).
One drawback of performing color correction after demosaicing is that the reduction in spatial resolution caused by crosstalk cannot be corrected. Color correction processing is performed on each individual pixel location independently of that pixel location's neighboring pixel locations, so there is no adjustment of the color intensity values associated with the pixel location based on the color intensity values stored in the neighboring pixel locations.
As the foregoing illustrates, what is needed in the art is an improved approach for correcting for the effects of spectral, optical and electrical crosstalk in digital images.
For clarity, identical reference numbers have been used, where applicable, to designate identical elements that are common between figures. It is contemplated that features of any of the example embodiments may be incorporated in other embodiments without further recitation.